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Spring Boot集成Mybatis简洁版

概述

现在互联网应用中,大部分还是使用Mybatis来操作数据库的,本文介绍一下Spring Boot中如何集成Mybatis。

创建Spring Boot工程

在 Spring Boot 开篇-创建和运行一文中有一个小节介绍了如何使用Spring Boot的组件来创建工程。如果要集成Mybatis,只需要把Mysql和Mybatis这两个组件勾选一下即可。

当然也可以不通过这种方式,直接在POM.xml文件中添加依赖也是可以的。我选择的是直接在POM.xml文件中直接添加依赖这种方式。

dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
</dependency>

<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.34</version>
</dependency>

<dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.7</version>
</dependency>

数据源使用阿里的druid。完整的POM.xml文件内容如下:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.springboot</groupId>
    <artifactId>study</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>study</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.10.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.3.1</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.34</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.7</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>fastjson</artifactId>
            <version>1.2.45</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

创建table

CREATE TABLE `user` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(30) NOT NULL DEFAULT '',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=8 DEFAULT CHARSET=utf8 COMMENT='user信息';

创建entity

package com.springboot.entity;

public class User {
    private Long id;
    private String name;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '/'' +
                '}';
    }
}

创建Mybatis映射文件和repo

UserRepo.java

package com.springboot.repo;

import com.springboot.entity.User;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Component;

import java.util.List;

@Component
@Mapper
public interface UserRepo {
    int insert(User user);

    User selectByPrimaryKey(Long id);

    int updateByPrimaryKey(User user);

    int deleteByPrimaryKey(Long id);

    List<User> selectAll();
}

UserMapper.xml

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd" >
<mapper namespace="com.springboot.repo.UserRepo" >
    <resultMap id="BaseResultMap" type="com.springboot.entity.User" >
        <id column="id" property="id" jdbcType="BIGINT" />
        <result column="name" property="name" jdbcType="VARCHAR" />
    </resultMap>

    <sql id="Base_Column_List" >
        id,
        name
    </sql>

    <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="java.lang.Long" >
        select
        <include refid="Base_Column_List" />
        from user
        where id = #{id,jdbcType=BIGINT}
    </select>

    <select id="selectAll" resultMap="BaseResultMap">
        select
        <include refid="Base_Column_List" />
        from user
    </select>

    <update id="updateByPrimaryKey" parameterType="com.springboot.entity.User" >
        update user
        <set>
            <if test="name != null" >
                `name`= #{name,jdbcType=VARCHAR},
            </if>
        </set>
        where id = #{id,jdbcType=BIGINT}
    </update>


    <delete id="deleteByPrimaryKey" parameterType="java.lang.Long" >
        delete from user
        where id = #{id,jdbcType=BIGINT}
    </delete>


    <insert id="insert" parameterType="com.springboot.entity.User" useGeneratedKeys="true" keyProperty="id">
        insert into user
        <trim prefix="(" suffix=")" suffixOverrides="," >
           name
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides="," >
            #{name,jdbcType=VARCHAR}
        </trim>
    </insert>
</mapper>

编写application.properties

在Spring Boot为我们生成的application.properties文件中添加如下内容：

spring.datasource.name=spring_boot_study   spring.datasource.url=jdbc:mysql://localhost:3306/test   spring.datasource.username=root   spring.datasource.password=xxxxxx   spring.datasource.driver-class-name=com.mysql.jdbc.Driver   spring.datasource.type=com.alibaba.druid.pool.DruidDataSource   mybatis.mapper-locations=classpath:mapper/*.xml   mybatis.type-aliases-package=com.springboot.entity

单元测试

package com.springboot;

import com.springboot.entity.User;
import com.springboot.repo.UserRepo;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
public class UserTest {
    @Autowired
    private UserRepo userRepo;

    @Test
    public void testInsert() {
        User user = new User();
        user.setName("test2");
        userRepo.insert(user);
    }

    @Test
    public void testUpdate() {
        User user = new User();
        user.setId(6L);
        user.setName("test3");
        userRepo.updateByPrimaryKey(user);
    }

    @Test
    public void testDelete() {
        userRepo.deleteByPrimaryKey(6L);
    }

    @Test
    public void testSelectByPrimaryKey() {
        User user = userRepo.selectByPrimaryKey(7L);
        System.out.println(user);
    }

    @Test
    public void testSelectAll() {
        List<User> userList = userRepo.selectAll();
        System.out.println(userList);
    }


}

直接运行单元测试,验证集成Mybatis是否成功即可。